The main direction of the project is immunological, involving complement interactions wth immune systems as part of a continuing interest in the autoimmune diseases and the role of serum complement. The ultrastructural applications include the electron microscope studies of human complement components and their molecular interaction with each other and immunoglobulins. The first project concentrates on the ultrastructures of Clq and its interaction with immunoglobulins. Project (2) involves a morphological study of Bordetella pertussis including localization of the biologic activities of lymphocytosis and histamine sensitization to one of three structural entities present in the bacterial cell wall and liquid culture (supernatants). This collaborative study with Dr. S.I. Morse (Downstate Medical Center) has already achieved purification of this ultrastructural particle called LPF for lymphocytosis promoting factor. Monospecific antisera have been prepared to LPF and further immunochemical and biological correlations will be studied with this factor as well as the other two ultra-structural particles. The lymphocytosis promoting factor (LPF) has been found to be mitogenic fo T lymphocytes in mice and is also mitogenic for human peripheral blood lymphocytes. Project (3) is concerned with the immunosuppressive properties of human chorionic gonadotropin (hCG). In collaboration with Dr. Robert Canfield, crude hCG was found to be more inhibitory to stimulated human lymphocytes than purified hCG. The crude hCG is being fractioned to see if this inhibitory activity can be localized to a single biologically relevant substance. BIBLIOGRAPHIC REFERENCES: Morse, S.I. and Morse, J.H. Isolation and properties of the leucocytosis and lymphocytosis - promoting factors of Bordetella pertussis. In press. J. Exp. Med. June, 1976. Canfield, R.E., Birken, S., Morse, J.H. and Morgan, F.J. Human chorionic gonadotropin In: "Proceedings of the Symposium on Drug Action-Peptide Hormones" (J. Parsons, Ed.) pp. 299-315. MacMillan and Co., London, 1976.